Error "Unresponsive Script" while first start

Hi
I wanted to download, install and run Zimbra Desktop. When I first wanted to open it, an Error Window like shown appeared: Bildschirmfoto 2013-07-04 um 11.46.22.png
I could stop the script or continue, but nothing happened ...
I had this problem on OS X 10.8.4 and on Windows 7 Professional 64bit.
Could anyone please help me? I don't know what doesn't work exactly.
Thanks!
Peter